Non-orthogonal multiple access (NOMA) is a wireless bandwidth sharing technique wherein multiple users can concurrently occupy channel bands, with each user optionally encoded by error detection/correction coding, e.g., forward error correction (FEC), and can be sorted at a receiver, by the receiver applying for example a successive interference cancellation (SIC) or other known techniques. This concurrent time-frequency use contrasts to multiplexing techniques such as time-division multiple access (TDMA), frequency-division multiple access (FDMA), and orthogonal frequency-division multiple access (OFDMA), which generally allocate per-user frequency bands, or time slots, or both.
In conventional NOMA techniques, considerable cost can be required for system design and system configuration, to meet performance goals. Such design and system configuration effort can assume a single user scenario, and can identify optimum system parameters for that scenario. Reasons include certain system parameters being fixed, i.e., not sufficiently controllable for effective adaptation to rapidly changing environments, such as the number of concurrent users. Unwanted results can include under-utilization of system resources during light loading intervals, because the system is constructed and configured for a worst-case scenario, and its resources are fixed accordingly. Therefore, current needs include NOMA with substantially increased adaptiveness.